The importance of minimizing the influence of frictional forces on the safety release of a safety release ski binding are explained in my prior U.S. Pat. No. 3,730,543, the contents of which are incorporated herein by reference. As explained in my prior patent, the two functions of (a) clamping the ski boot firmly to the ski during normal maneuver and (b) the release of the clamping action to permit the boot to disengage from the ski to save the leg from injury are only incompletely realized with prior art safety bindings in which the boot sole rests on the ski. To minimize the influence of the frictional forces on the safety release, my aforementioned patent disclosed a step-in safety binding with toe and heel units so constructed that the bottom of the ski boot is kept out of contact with the surface of the ski.